1. Field of the Invention
The present invention relates to an information processing technique for providing information about a route through a network such as the Internet.
2. Description of the Related Art
Conventionally, navigation systems are well-known as a means for providing information (route guidance) about a route from a current point to a plurality of predetermined destinations or way points (to be referred to as destinations hereinafter).
As a characteristic feature, a navigation system can flexibly change the destination. To take advantage of this characteristic feature, the user interface of a normal navigation system is designed to change and re-find the destination in accordance with the same procedures used in a prior route search. That is, the user interface is designed to receive route guidance following a setting change from the current point to a newly changed destination (e.g., Japanese Patent Laid-Open No. 2003-139552).
An operation example will be described, in which route search is executed by first setting the destination to BBB, and receiving route guidance. Then, en route to the destination (BBB), destination AAA is added, and still another destination CCC is also added. To re-execute the search in this situation using the navigation system, the user performs the following operations.
(1) Set a route, current point No. 1→AAA→BBB and re-execute search.
(2-1) Destination CCC is added before visiting destination AAA
Set a route, current point No. 2→AAA→CCC→BBB again and re-execute search.
(2-2) Destination CCC is added after visiting destination AAA
Clear setting (1), set a route, current point No. 3→CCC→BBB again, and re-execute search.
By re-executing the search according to the above procedures, the user can receive route guidance after a change.
One example application of such route guidance by a navigation system is route guidance by Internet service through a Web browser. For example, travel agencies can provide an Internet service to offer geographic information to tourists using route guidance through a Web browser. The travel agencies can also provide this Internet service as part of a travel service.
If a travel agency provides this service, a user can easily acquire geographic information as route guidance from the current location of the travel agency to the destination by going to the travel agency and requesting route search to receive route guidance to the destination.
However, conventional navigation systems are designed to re-execute route search including information regarding locations already visited. Hence, in some cases, the user must go to a predetermined destination through the same route. For example, the search re-execution in case (2) is not performed in consideration destination AAA, which was already visited. Instead, a route to minimize the distance to destination CCC is provided. For this reason, route guidance with the same route as one already traversed may be provided.
In particular, a user who wants the above-described route guidance service of a travel agency must go to the agency to obtain the service. From there, with high probability, the user can take the same route.
However, it would be preferable for a user. (i.e., a tourist) to not waste time visiting an unknown place by traveling via the same route. In such a case, preferably route guidance should, as much as possible, exclude passage through the same route.
Normally, each area has only one travel agency. Thus, to obtain route guidance to a destination, the user inevitably goes to the same place. In consideration of this fact, not only a specific travel agency but also a plurality of sites (e.g., convenience stores) would preferably offer the service to provide geographic information as route guidance.